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[linux-dvb] tzap status output - what does it all mean?
Please excuse the dumb newbie question, but what do the numbers coming
out of tzap mean and what should the values be? (snr, ber, unc)
I have a Nova-T with the Conexant chipset. After much messing about
with CVS checkouts of dvb-kernel and video4linux, and a 2.6.10 kernel
compiled from source (all on Debian unstable, BTW) I have a kernel and a
set of modules that seem to work. I can
tzap "BBC ONE" -r
and
cat /dev/dvb/adapter0/dvr0 > /store/tv.ts
and then sometimes if I rename the tv.ts to tv.mpeg, Window Media Player
on another PC can play some TV. (The PC with Linux and the nova-t in it
is only a 400MHz PII, and has no monitor attached...) Most of the time
Media Player refuses to open the file though.
I've got the aerial right by the computer which is downstairs, which
obviously isn't ideal (I can get some sort of signal by pointing it out
of the window, which is about 90 degrees away from the transmitter, but
does produce a picture when I have the nova-t in my Windows PC). So I
carried everything up into the loft and pointed the aerial in the
general direction of the Sandy Heath transmitter. From there, tzap
reports something like this (from memory):
status ?? | signal 004f | snr ffff | ber 00000000 | unc 00000100 |
FE_HAS_LOCK
(I can't remember what the status value was).
If I point the aerial 90 degrees away from the transmitter then snr
drops a bit from ffff, ber becomes 00001400, and unc remains at
00000100. It looks to me like unc can't go above 0100?
I recorded the output from dvr0 to a file while the ber was equal to
00000000, and Media Player refuses to play it (so does vlc). The output
from dvbsnoop seems to suggest that the the file is very corrupted
(though there's a lot of output from dvbsnoop, and I'm new to this game...).
So to my original question, what does it mean if snr=ffff, ber=0 and unc
is stuck at 0100? I guess ber and unc ideally should both be zero?
Should snr be a high value or low? What's a good value for the signal
reading? An snr of ffff looks like the maximum value, which looks a bit
bogus to me...?
--
Rob
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